When activating motor vehicle headlights, one should know whether or not a road is separated from the opposite lane by a structural separation. The specific light distribution of “highway light” is activated only at the moment when a certain speed threshold is exceeded. Legislators also allow highway lights to come on when a structural separation has been detected.
For headlight activating algorithms, it is important to know whether or not there is a structural separation: in the case of a structural separation, the headlights of other vehicles are often not discernible, so that the system is switched to high beams and there may thus be glare.
Navigation information may thus be utilized appropriately to detect a highway (or a structural separation, if necessary) but permanently installed navigation systems are often not present in vehicles of the lower price segment. A navigation system fails due to the problem of updating the map material in construction areas where there is a structural separation by concrete walls.
There are situations in which a distance measurement is appropriate. In addition to an assistant for transverse guiding (e.g., at construction sites, in parking garages), there are also assistants for longitudinal guiding (e.g., during parking, braking with (video) ACC to a standstill). Navigation systems cannot be used with the longitudinal and transverse guiding tasks mentioned above because of insufficient map data and/or precision of the GPS signals.
Parking aids are implemented at the present by ultrasonic sensors. Parking systems are expensive—although they only emit a warning sound through the music system. There are retrofitting systems, but those are also associated with increased costs. Parking assist systems are often installed only at the rear since drivers have better vision forward than rearward.
German patent document DE 10 2007 034 196 A1 discusses a method for lane detection having a driver assistance system, which includes a sensor system for lane detection in which measuring points representing lane markings are detected with the sensor system for lane detection in a region of traffic space ahead of the vehicle. An ideal number of measuring points MP is ascertained based on a reference model. A plausibility measure of the forward viewing range is determined from a comparison between the number of actually detected measuring points and the ideal number of measuring points.